Fluid container with contaminantcollecting means



E. F. WEBB 3,306,454 FLUID CONTAINER WITH CONTAMINANT-COLLECTING MEANSFeb. 28, 1967 Filed Sept. 24, 1962 la /IO '.w.....a.'1r1'."",rl/

INVENTOR.

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United States Patent fifice 3,306,454 Patented Feb. 28, 1967 3,306,454FLUID CONTAINER WITH CONTAMINANT- CLLECTING MEANS Edmond F. Webb, 25601Franklin Hill Drive, Franklin, Mich. 48025 Filed Sept. 24, 1962, Ser.No. 225,469 6 Claims. (Cl. 210-172) This invention relates tocontaminant-collecting means for containers of fluid, particul-arly forfuel tanks of vehicles, to retain contaminants in the fluid and toprevent them from passing out of the container with the fluid.

The use of fuel filters in fuel lines of vehicles for removingcontaminants is well known. Such filters commonly have been placed inthe line -between the fuel tank and the carburetor and, more recently,have been placed within the fuel tank at the inlet of the fuel supplyline. Filters of this nature must be capable of removing very finematerials from the fuel in order to keep the carburetor clean andproperly functioning and should also prevent fiow of water from the fueltank. The size of the particles which must be filtered out to keep thecarburetor functioning properly continues to be reduced asmultibarrelled carburetors become more commonplace; these have smallerybores and passages which tend to plug more easily. However, the finerfilters needed to remove the finer particles also tend to load up andplug easier.

The present invention relates to new contaminant-collecting means for afluid container, and particularly a fuel tank, which means removes mostof the contaminant particles from the fluid or fuel before they canreach and plug the fuel filter. This prolongs the life of the filter andenables t-he filtering action to be effective for a much longer timebefore enough contaminants are gathered thereon to affect theefficiency. The contaminant-collecting means of the invention comprisesa layer of material affixed to the bottom of the tank, forming amultiplicity of receptacles or shelters for the recption of contaminantparticles. The layer collects the particles lfrom suspension in the fuelas it lies above and moves across the layer, with the particles settlinginto the receptacles in the layer where they remain, usually for thelife of the fuel tank. The contaminant-collecting means also preferablyincludes a liquid which lays on the shelter-providing material and aidsconsiderably in absorbing or collecting contaminants in the tank.

It is, therefore, a principal object Iof the invention to providecontaminant-collecting means for a fiuid container to receive and retaincontaminants inthe fluid to prevent them from being removed from thecontainer with the uid.

Another object of the invention is to provide contaminant-collectingmeans on the bottom of a fuel tank which receives and holds contaminantsrfrom the fuel and prevents them from being gathered on and plugging afuel filter associated with a fuel supply line in the tank.

Other objects and advantages of the invention will be apparent from thefollowing detailed description of preferred embodiments thereof,reference being made to the accompanying drawing, in which:

FIG. 1 is an elevational View, with parts broken away and with parts incross section, of a fuel tank having contaminant-collecting meanstherein according to the principles of the invention;

FIG. 2 is a greatly enlarged view in ycross section of thecontaminant-collecting layer shown in FIG. 1;

FIG, 3 is a greatly enlarged View in cross section similar to FIG. 2 ofa slightly modified contaminant-collecting layer according to theinvention; and

F IG. 4 is a greatly enlarged, elevational view, with parts broken awayand with parts in cross section, of a further modifiedcontaminant-collecting layer embodying the principles of the invention.

While the invention is described 'below primarily in connection with afuel tank, it can be used in almost any application where it isdesiredto remove contaminants from a fluid held in a container. As adiverse example, the invention can be applied to wine bottles to holdand prevent dregs from being raised when bottles are moved or tilted.

The invention can also be applied to other fiuid systems besides fuelsystems, such as hydraulic systems. Hydraulic control systems, forexample, frequently e-mploy servo valves or other components whichrequire hydraulic fluid with a minimum amount and size of contaminantparticles. Such often require the use of a nominal 5-micron or anabsolute S-micron filter which is expensive and plugs easily. To achievea large capacity, a bypass filter is usually used, with perhaps 80% ofthe hydraulic fluid flowing through the by-pass filter and 20% flowingthrough the main filter. By employing contaminant-collecting meansaccording to the invention in the reservoir or sump of the system, theby-pass filter and associated piping frequently can be eliminated and asmaller main filter can sometimes -be used.

Filters have long been used in fuel supply lines between the fuel tankand the fuel pump and also between the fuel pump and the carburetor toremove contaminants from the fuel. Such filters previously have removedonly the larger particles in the fuel, which rarely occur, with theresult that relatively few particles were caught by the filter duringthe life of the vehicle; consequently, there was little danger that thefilter or line would become plugged.

In more recent years, the filters have ibeen used within the fuel tankat the entrance to the fuel supply line therein. The use of the fuelfilter in the fuel tank enables it to be washed by the fuel as itsloshes back and forth past the filter so that at least some of the dirtparticles gathered thereon are removed. This is particularly importantfor fine filters which are now required to remove particles as small asapproximately 10 microns or 0.0004 which can cause flooding, sticking,and clogging.

This position of the filters also has been important particularly forfilters which are capable of preventing the flow of water therethrough.If such filters were used in the fuel line, they would soon block enoughwater to prevent the ow of fuel. However, with the filter at the inletend of the fuel supply line, the blocked water remains in the fuel tankand eventually disappears, mainly when it sloshes upwardly on the sidesof the tank, during movement of the vehicle, and evaporates. A smallamount of the water also apparently goes into solution in the gasolineand is supplied to the engine therewith. any event, the water neverac-cumulates in the tank to the extent that it blocks the flow of fuelinto the fuel supply line.

The present invention provides contaminant-collecting means comprising alayer of material affixed to the bottom of ythe fuel tank to catch andto retain substantially all of the contaminants in suspension in thefuel. The layer thereby provides a positive means for receiving andretaining the contaminants even Ibefore they have a chance to reach themain filter for the fuel. The contaminant-collecting layer includes amultiplicity of receptacles or shelters into which contaminant particlesin the fuel settle and remain out of circulation or movement of the fuelin the tank. A substantially integral layer of material therebygradually builds up on the contaminant-collecting layer during the lifeof the vehicle, which material will not lgo back into suspension witheven the most severe jarring of the tank.

The contaminant-collecting means also preferably includes acontaminant-collecting liquid which also lies on the bottom of the tankand increases the ability of the collecting means to gather and holdcontaminants. The liquid, such as glycerine and water, also may increasethe attraction of the layer for water with the combination of theglycerine and water apparently collecting and holding contaminantparticles more effectively than either the glycerine or water alone. Theglycerine and water, in a ratio of 2 to l, is preferably used in anamount of about four ounces per square foot of the layer. Further, onlyabout two square feet of the layer is sufficient for a ZO-gallon fueltank, so that the increase in cost for the glycerine is negligible.

The shelter-providing layer preferably wets out and distributes theliquid when it is deposited thereon and retains it in a distributedcondition on t-he bottom of the tank, even though only a minute amountof liquid is employed. Further, uniformity of the distribution of theliquid is achieved even though the bottom of the tank has reinforcinggrooves or ridges. The layer thus provides maximum effectiveness .forthe liquid by exposing a maximum surface of it to the contained fluidand also substantially prevents migration of the liquid even though thetank is at an angle, if the vehicle is parked on a severe slope for along period, for example. In addition, the layer prevents the liquidfrom sloshing on the sides of the tank and possibly evaporating, therebyleaving a contaminant residue which is again subject to passing throughthe filter.

The contaminant-collecting means, which includes thecontaminant-collecting layer and the liquid, also collect `gummy,gelatinous material which is sometimes `formed in the fuel, at least inthe case of gasoline, and which tends to plug the filters or to affectcarburetor operation. This gummy material is believed to lbe produced`from certain gasoline additives and accelerated by water and air-bornefungi. Because the fungi require water for propagation, and because anywater in the tank will settle in the contaminant-collecting layer, thegelatinous growth, if any, will occur in the receptacles of the layerand be trapped therein as they grow. The contaminant-collecting layeralso can :be impregnated or treated with fungicide to inhibit thegelatinous Vgrowth in the first place.

Referring to the drawings, and more particularly to FIG. 1, a liuidcontainer or fuel tank includes a lower half 12 and an upper half 14which are joined at their periphery by suitable means such as welding.The tank 10 includes a conventional filler pipe 16, through which fuelis added to the tank 10, and a fuel outlet line 18, from which fuel isremoved from the tank 10 and is supplied to an engine of a vehicle whichcarries the tank. A fuel filter 20 is located at the opening of the fuelsupply line 18 to prevent contaminants, including dirt and water, fro-mentering the line 18. This filter can be of many suitable typesincluding that disclosed in E. F. Webb Patent 2,788,125. In any event,the filter, as previously pointed out, is one which prevents passage ofWater through the line 18 and prevents passage of solid contaminants inexcess of approximately 10 microns. While the filter 20 is shown withinthe tank 10, to provide the advantages discussed above, it can also belocated at some other point in the supply line 18.

In a-ccordance with the invention, a contaminant-collecting meansconstituting a layer 22 is affixed to the bottom half 12 of the tank 10to collect contaminants in the gasoline before the contaminants have achance to gather on the filter 20. The contaminants settle down into thelayer 22 and remain there for the life of the vehicle.

In the embodiment shown greatly enlarged in FIG. 2, thecontaminant-collecting layer 22 includes a thin plastic sheet 24 whichhas a thickness in the order of 4 to 8 mils. A multiplicity of short,particulate fibers 26 are electrostatically flocked on an upper surfaceof the sheet 24 by means known in the art. The lower ends of the fibers26 are affixed to the sheet 24 by a suitable adhesive while the fibers26 are retained in their upright positions by the electrostatic field.Not all of the fibers remain upright, some lying at a narrow angle tothe surface of the sheet 24, as shown. After the upper side o-f thesheet 24 is fiocked, the lower side is coated with a suitable adhesive28 and is then adhered to the bottom half 12 of the tank 10. Theadhesive can be of many suitable types, many commercially-availableepoxy resin adhesives being suitable for the purpose. If desired, theadhesive 28 can be sprayed on the bottom half 12 and the sheet 24 thenplaced in the half 12 against the adhesive or a pressure sensitiveadhesive may be used. Also, the layer 22 can be affixed to the bottomhalf 12 of the tank 10 by mechanical engagement, such as by means ofsmall barbs welded to the bottom half 12, which barbs engage the layer22 when pressed thereon. The contaminant-collecting layer may also bemade integral with the container.

The fibers 26 and the sheet 24 form small receptacles or shelters 30 inwhich the contaminants in the fuel settle and are held. After receivingcontaminant particles, the receptacles 30 hold them therein out of thepath of the fuel moving above the top ends of the fibers 26 when thevehicle is in motion. During extremely violent motions Of the vehicle,the fuel will stir up some particles from the receptacles 30 and causethem to again go into solution. However, such occurrences are rare andin between them the contaminant .particles settle and form a :more orless integral substance in the receptacles 30. The slanted fibers 26further aid in holding the contaminants near the sheet 24 in thereceptacles 30.

The layer 22 is designed to have an area sufficient that even over thelife of a vehicle, the contaminants in the fuel will not fill the layer22 to any extent, so that the function of the fibers 26 and thereceptacles 36 will not be seriously inhibited. In practice, if the areaof the layer 22 is approximately four square feet, with fibersone-quarter inch in length, the contaminants will never become thickenough to be detrimental to the action of the layer 22.

A slightly modified layer 32 of a contaminant-collecting material isshown in FIG. 3. The layer 32 includes a fabric backing 34 with which isinterlocked upstanding fibers 36, which may be in the form of a yarn ortwisted fibers, as shown. A plurality of receptacles 38 formed by thebacking 34 and the fibers 36 again constitute shelters for contaminantssettling out of the gasoline. The layer 32 is affixed to the bottom half'12 of the tank 10 by adhesive or by suitable mechanical connections.

As in the case of the layer 22, the fibers 36 of the layer 32 not onlyhelp form the receptacles 38 but their upper ends tend to inhibit the owof fuel so that the motion, if any, of the fuel in the immediatevicinity will be decreased to help enable contaminants carried therebyto settle into the receptacles 38. The fibers 36 also tend to preventany abnormal sloshing of the fuel from stirring up the contaminants inthe receptacles.

A further modified contaminant-collecting layer 40 is shown in FIG. 4.The layer 40 constitutes fine-celled foam 42 containing -a multiplicityof minute, inter-communicating cells 44. The cells 44 are shown greatlyenlarged with respect to the remainder of FIG. 4 in order to illustratethat they communicate with one another, which is essential for theproper functioning of the layer 4t). Receptacles 46 are formed in thelower portions of the layer 48 by the cells 44, the receptacles 46 againconstituting shelters for contaminants in the fuel. As contaminants inthe fuel settle therefrom, they are collected by the cells 44 andgradually drift downwardly into the receptacles 46 so that they remaintherein and out of circulation.

The foam layer 4G has the advantage of holding the contaminants evenmore effectively than the layers 22 and 32, but does not inhibit themotion of contiguous fuel since the foam layer 40 has `no upstandingfingers or fibers. The foam can be of rubber or of polyurethane, forexample, with a vinylidene chloride foam also being suitable, such foambeing obtained from the Dow Chemical Company under the name Saran. Inaddition to the above three, other contaminant-collecting layers forminga multiplicity of shelters can be used, a thin honeycomb structure beingan example of such.

The contaminant-collecting liquid of the collecting means must beimmiscible with the contained liquid and should not freeze or vaporizeat most of the temperatures to which the container is subjected. Thecollecting liquid should also have suiciently low surface tension toenable it to collect contaminants and must Ihave a specific gravityhigher than that of the contained liquid to cause the collecting liquidto `be at the Ibottom of the container and receive contaminants settlingtherein. In addition, in the case of a fuel tank, the liquid should notaliect any water in the tank in a manner to enable it to pass throughthe fuel lter, by acting as a wetting agent or the like. While notessential, the collecting liquid preferably should not be miscible withthe water at all. Other desirable properties of the collecting liquidinclude being inexpensive, immiscible in alcohol, and non-reactive withthe container. The liquid, particularly if a solution, should also behygroscopic or deliquescent in order not to be deprived of its water ofsolution.

By way of illustration and not limitation, substances which have beenfound to be suitable, in addition to glycerine, are glycol; glycericacid; derivatives of glycerol, glyceric acids, and glycol includingglycerol ether, glycol monoacetate, glycol monoformate, glycerolmonoacetate, ethyl ester glyceric acid, and methyl ester glyceric acid;sodium chloride with sodium nitrite which tends to ybe non-corrosive andhas a lower freezing point; and some hydroxides, -particularly sodiumhydroxide, potassium hydroxide, and lithiumy hydroxide. Those having laknowledge of the art can choose other suitable liquids, once they areaware of the proper characteristics discussed above.

The effectiveness of the contaminant-collecting layers has Vbeen provenin many tests. In typical tests, a layer of -a contaminant-collectingmaterial, such as shown in FIGS. 2-4 of the drawing, was placed in thebottom of a test tank which also contained a fuel supply line with afilter. The filter produced an initial pressure drop of 0.45" ofmercury. The tank was shaken during the tests to simulate drivingconditions and dust was added thereto at a rate of 1/16 teaspoon (0.218gram) every minute while the fuel pump was stopped for a period of eightseconds. Without a contaminant-collecting layer at the bottom, thepressure drop produced by the filter reached 1.47" of mercury, theamount consider to be a desired maximum, when from 31/2 to 41/2 grams ofdust had been added. However, with the contaminant-collecting layer, 14grams of dust were added without any increase in pressure drop at all.

Various modifications of the above described embodiments of theinvention will be apparent to those skilled in the art and it is to beunderstood that such modifications can be made without departing fromthe scope of 6 the invention, if they are within the spirit and tenor ofthe accompanying claims.

What I claim is:

1. In a fuel tank, conduit means coupled to the tank for withdrawingfuel from the tank, a layer of cellular material aiiixed to the bottomof the tank and having a multiplicity of randomly disposedintercommunicating cells positioned throughout said layer, saidmultiplicity of randomly disposed intercommunicating cells forming amultiplicity of labyrinth-type receptacles in said material withupwardly facing openings in the top of said layer for receiving andholding contaminants from the fuel whereby dislodgement of contaminantsheld in said receptacles by movement of iiuid in the fuel tank isminimized.

2. The combination of claim 1 in which the bottom surface of said layerof cellular material is affixed to the bottom of said tank to provide aclosed bottom surface for said layer of cellular material.

3. The combination of claim 2 in which said conduit means forwithdrawing fuel from the tank comprises a fuel line having an openingtherein and in which a fuel filter is connected to the opening lof saidfuel line for filtering contaminants from fluid passing into said fuelline from said tank.

4. The combination of claim 1 in which said layer of cellular material`is synthetic plastic foam material.

5. The combination of claim 1 in which the bottom surface of said layerof cellular material is adhered to the bottom of said tank by anadhesive material to thereby provide a closed bottom surface for saidlayer of cellular material.

6. 'The combination of claim 5 in which said layer of cellular materialis synthetic plastic foam material.

References Cited by the Examiner UNITED STATES PATENTS 1,235,438 7/1917Chynoweth 210-172 1,315,623 9/1919 Cobb 208-188 1,822,452 9/ 1941Pelletier 210-296 X 2,546,874 3/ 1951 Siegrist 210-457 X 2,788,1254/1957 Webb 210-460 X 2,923,411 2/1960 Oster. 3,165,468 1/ 1965 Strader210-172 FOREIGN PATENTS 692,147 10/ 1930 France.

648,417 1/ 1951 Great Britain.

858,127 1/ 1961 Great Britain.

OTHER REFERENCES Greg-cry: Uses and Applications of Chemicals andRelated Materials, 1939, Reinhold, New York, pp. 300- 302, 275, 276.

REUBEN FRIEDMAN, Primary Examiner.

H. L. MARTIN, Examiner. E, MEDLEY, Assistant Examiner,

1. IN A FUEL TANK, CONDUIT MEANS COUPLED TO THE TANK FOR WITHDRAWINGFUEL FROM THE TANK, A LAYER OF CELLULAR MATERIAL AFFIXED TO THE BOTTOMOF THE TANK AND HAVING A MULTIPLICITY OF RANDOMLY DISPOSEDINTERCOMMUNICATING CELLS POSITIONED THROUGHOUT SAID LAYER, SAIDMULTIPLICITY OF RANDOMLY DISPOSED INTERCOMMUNICATING CELLS FORMING AMULTIPLICITY OF LABYRINTH-TYPE RECEPTACLES IN SAID MATERIAL WITHUPWARDLY FACING OPENINGS IN THE TOP OF SAID LAYER FOR RECEIVING ANDHOLDING CONTAMINANTS FROM THE FUEL WHEREBY DISLODGEMENT OF CONTAMINANTSHELD IN SAID RECEPTACLES BY MOVEMENT OF FLUID IN THE FUEL TANK ISMINIMIZED.